Common subdirectories: ../zlib-1.2.11/amiga and ./amiga
diff -u ../zlib-1.2.11/CMakeLists.txt ./CMakeLists.txt
--- ../zlib-1.2.11/CMakeLists.txt	2017-01-15 09:29:40.000000000 +0100
+++ ./CMakeLists.txt	2021-03-24 15:24:48.190291072 +0100
@@ -183,10 +183,12 @@
     set(ZLIB_DLL_SRCS ${CMAKE_CURRENT_BINARY_DIR}/zlib1rc.obj)
 endif(MINGW)
 
-add_library(zlib SHARED ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_DLL_SRCS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
-add_library(zlibstatic STATIC ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
-set_target_properties(zlib PROPERTIES DEFINE_SYMBOL ZLIB_DLL)
-set_target_properties(zlib PROPERTIES SOVERSION 1)
+add_library(zlib ${ZLIB_SRCS} ${ZLIB_ASMS} ${ZLIB_PUBLIC_HDRS} ${ZLIB_PRIVATE_HDRS})
+if (BUILD_SHARED_LIBS)
+    target_sources(zlib PRIVATE ${ZLIB_DLL_SRCS})
+    set_target_properties(zlib PROPERTIES DEFINE_SYMBOL ZLIB_DLL)
+    set_target_properties(zlib PROPERTIES SOVERSION 1)
+endif()
 
 if(NOT CYGWIN)
     # This property causes shared libraries on Linux to have the full version
@@ -201,7 +203,7 @@
 
 if(UNIX)
     # On unix-like platforms the library is almost always called libz
-   set_target_properties(zlib zlibstatic PROPERTIES OUTPUT_NAME z)
+   set_target_properties(zlib PROPERTIES OUTPUT_NAME z)
    if(NOT APPLE)
      set_target_properties(zlib PROPERTIES LINK_FLAGS "-Wl,--version-script,\"${CMAKE_CURRENT_SOURCE_DIR}/zlib.map\"")
    endif()
@@ -211,7 +213,7 @@
 endif()
 
 if(NOT SKIP_INSTALL_LIBRARIES AND NOT SKIP_INSTALL_ALL )
-    install(TARGETS zlib zlibstatic
+    install(TARGETS zlib
         RUNTIME DESTINATION "${INSTALL_BIN_DIR}"
         ARCHIVE DESTINATION "${INSTALL_LIB_DIR}"
         LIBRARY DESTINATION "${INSTALL_LIB_DIR}" )
Common subdirectories: ../zlib-1.2.11/contrib and ./contrib
Common subdirectories: ../zlib-1.2.11/doc and ./doc
Common subdirectories: ../zlib-1.2.11/examples and ./examples
Common subdirectories: ../zlib-1.2.11/msdos and ./msdos
Common subdirectories: ../zlib-1.2.11/nintendods and ./nintendods
Common subdirectories: ../zlib-1.2.11/old and ./old
Common subdirectories: ../zlib-1.2.11/os400 and ./os400
Common subdirectories: ../zlib-1.2.11/qnx and ./qnx
Common subdirectories: ../zlib-1.2.11/test and ./test
Common subdirectories: ../zlib-1.2.11/watcom and ./watcom
Common subdirectories: ../zlib-1.2.11/win32 and ./win32
Only in ./: ZLIB.patch